The present invention relates to a motor vehicle heat exchanger system.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Against the backdrop of increasingly scarce fossil resources and legal requirements with regard to CO2 emissions from motor vehicles, measures to increase the overall efficiency of motor vehicles are becoming ever more important. About two-thirds of the chemically bound energy to drive a motor vehicle is lost in the form of combustion heat and frictional heat. There have therefore been efforts for a long time to better utilize the exhaust gas heat and to use it to increase the efficiency of motor vehicles. In addition to concepts for direct energy recovery (thermoelectrics, Rankine), measures provide, in conjunction with the thermal management of motor vehicles for example, options to use waste heat for interior heating or the shortening of cold-start phases. Thus, the shortening of cold-start phases by an accelerated warm-up of lubricants, such as motor or transmission oil, can take place, whereby a reduction of friction loss can be obtained.
DE 10 2011 103 110 B4 discloses an exhaust gas system for an internal combustion motor of a motor vehicle with a circulation heat pipe. The exhaust gas system has an exhaust gas pipe, a condenser, and an evaporator, as well as lines connecting the condenser and the evaporator. Heat transport of the heat energy extracted from the exhaust gas takes place via a working medium. The evaporator is formed of an exhaust gas pipe, a capillary structure and a cladding tube. The capillary structure is constructed as a porous body between the exhaust gas pipe and the enveloping body, in which the working medium crosses over from a fluid state into a gas or rather vapor state when passing through the capillary structure.
The heat pipe works simply by introduction of heat without mechanical pumping of the working medium. This is possible through the use of a capillary structure in the evaporator, which compensates for the flow pressure loss of the working medium through the capillary pressure. The heat pipe is generally constructed concentrically with an internal gas guide or rather internal bypass. This leaves only a one-sided heat dissipation from the inside to the outside. The manufacture of tubular capillary structures also takes considerable effort.
It would therefore be desirable and advantageous to provide an improved motor vehicle heat exchanger system which obviates prior art shortcomings and which is simple in construction and lightweight while yet being reliable in operation.